The present invention relates to the telecommunications arts. The preferred embodiment of the invention finds particular application in conjunction with a portable telecommunication device such as an analog or digital cellular, wireless, etc. telephone with a piezo-electric transducer for handsfree and private operating modes, and will be described with particular reference thereto. However, the present invention finds application with other devices such as pagers, personal organizers, portable CD/DVD players, portable or palm-top computers, etc.
The handsfree mode of operation refers to the ability of a device to generate dispatch-level audio output, whereas the private mode of operation refers to the ability of a device to generate private-level audio output. It is desirable to provide portable (e.g. hand held) devices with both handsfree and private operating modes. It is also desirable to provide portable devices with small form factors. However, in small form factor devices, the space available to house both handsfree and private mode transducers is acoustically small.
That is, a conventional speaker includes a fairly compliant or flexible structure that can be modeled as a weak spring having a low stiffness. In contrast, a small, enclosed volume of air can be modeled as a spring having a low compliance or an extremely high stiffness. Accordingly, an acoustically small space, such as those found in most portable devices, has a very high stiffness. If a conventional speaker, having a low stiffness, is mounted within a volume of air having a greater stiffness than the speaker, the volume of air acts to disadvantageously shift the resonance of the speaker higher, thereby limiting the effective audio bandwidth in a handsfree operating mode.
Accordingly, it is considered desirable to provide a new and improved telecommunication device with a piezo-electric transducer for handsfree and private operating modes, that meets the above-stated needs and overcomes the foregoing difficulties and others while providing better and more advantageous results.
In accordance with one aspect of the present invention, a device for generating dispatch-level audio output in a handsfree operating mode is disclosed. The device includes a housing, a cantilevered bender having a first end and a second end wherein the first end of the bender is mounted to the housing, a diaphragm having a first end and a second end wherein the first end of the diaphragm is attached to the second end of the bender, and a surround joining the second end of the diaphragm to the housing. The bender drives the diaphragm in a reciprocating manner to generate dispatch level audio output.
In accordance with another aspect of the present invention, a telecommunication device is disclosed. The telecommunication device includes a housing and a dual earpiece arrangement associated with the housing. The dual earpiece arrangement includes a handsfree transducer that generates dispatch-level audio output in a handsfree operating mode of the telecommunication device, and a private-mode transducer that generates private-level audio output in a private operating mode of the telecommunication device.
One advantage of the present invention is the provision of a telecommunication device including an elastically supported rigid diaphragm driven by a low compliance cantilevered piezo-electric handsfree transducer capable of producing wideband audio in a very small acoustic space.
Another advantage of the present invention is the provision of a telecommunication device including a coaxial handsfree and private mode transducer having two separate piezo-electric elements.
Yet another advantage of the present invention is the provision of a telecommunication device including a coaxial handsfree and private mode transducer having two separate piezo-electric elements incorporated into a single bender assembly.
Still further advantages of the present invention will become apparent to those of ordinary skill in the art upon reading and understanding the following detailed description of the preferred embodiment.